1. Field of the Invention
The present invention relates to an apparatus for breaking chips produced by cutting metallic workpieces, into small fragments, and a system for treating the chips.
2. Related Art Statement
When a machine tool such as a lathe, a drilling machine, a milling machine, or a planing machine cuts metallic workpieces or blanks, a large amount of chips are produced. In many cases, those chips are so sharp and are very difficult to treat. Elongate noodle-like chips are particularly difficult to treat. Hence, there have been known two sorts of apparatuses each for breaking chips into small fragments that are easy to treat. One known apparatus includes two rotary cutters which are rotated in opposite directions, respectively, to shear chips and thereby break the same into fragments. The other known apparatus includes a fixed cutter and a rotary cutter which is rotated relative to the fixed cutter to shear chips.
However, the above-indicated two known apparatuses have the problem that it is difficult for the two cutters to bite noodle-like chips which are entangled with one another or break those chips into fragments. In addition, since the known apparatuses break chips primarily by shearing, the broken chips or the fragments are so sharp and are very difficult to treat. For example, the sharp fragments may hurt the hands of workers, or may engage one another so strongly that they are difficult to separate. Meanwhile, it has been practiced that broken chips or fragments are conveyed by utilizing an air flow. In this case, sharp fragments hurt or damage the inner surface of a tube member that forms a chip-convey passage, thereby lowering the life expectancy of the tube member. In a particular case where the tube member is provided by a hose formed of an organic material, for the purpose of giving some flexibility to the chip-convey passage, sharp fragments largely lower the life expectancy of the hose.
The present invention has been developed in the above-described background.
The present invention provides a chip breaking apparatus and a chip treating system which have one or more of the technical features that are described below in respective paragraphs given parenthesized sequential numbers (1) to (35). Any technical feature which includes another technical feature shall do so by referring, at the beginning, to the parenthesized sequential number given to that technical feature. Thus, two or more of the following technical features may be combined, if appropriate. Each technical feature may be accompanied by a supplemental explanation, as needed. However, the following technical features and the appropriate combinations thereof are just examples to which the scope and spirit of the present invention are by no means limited.
(1) According to a first feature of the present invention, there is provided an apparatus for breaking chips into fragments, comprising an outer structure which is fixedly provided such that a center line of the outer structure is parallel to a reference direction having a vertical component; an inner structure which is provided inside the outer structure such that the inner structure is concentric with the outer structure; a rotary drive device which rotates, in a rotating direction, the inner structure about the center line; and the inner structure including a central portion which is concentric with the outer structure, and a plurality of blades which extend radially outwardly from an outer circumferential surface of the central portion and each of which is inclined relative to the rotating direction such that a lower surface of the each blade can be seen as viewed from a downstream side of the each blade in the rotating direction. When the inner structure is rotated, respective leading edges of the blades (i.e., respective downstream-side ends of the blades in the rotating direction) strike and break respective portions of elongate noodle-like chips entangled with one another, or engage and draw the same, thereby separating the same from the respective remaining portions of the chips into considerably small fragments. In addition, since each of the blades is inclined relative to the rotating direction such that the lower surface of the each blade can be seen as viewed from the downstream side of the each blade in the rotating direction, the each blade being rotated functions to draw the chips downward. Moreover, an air flow generated by the rotation of the blades contributes to drawing the chips downward and separating the same from one another. In the case where the chip breaking apparatus in accordance with the first feature (1) is provided on an upstream side of a chip breaking apparatus in accordance with the tenth feature (10) described later, the former chip breaking apparatus supplies, to the latter or downstream-side chip breaking apparatus, elongate noodle-like chips entangled with one another, while separating or breaking those chips into considerably small fragments.
(2) According to a second feature of the present invention, there is provided an apparatus for breaking chips into fragments, comprising an outer structure which is fixedly provided such that a center line of the outer structure is parallel to a first direction having a vertical component; an inner structure which is provided inside the outer structure such that the inner structure is concentric with the outer structure; a rotary drive device which rotates the inner structure about the center line; and the inner structure including a central portion which is concentric with the outer structure, a plurality of blades which extend radially outwardly from an outer circumferential surface of the central portion, and a plurality of separating portions which extend from the plurality of blades, respectively, in a second direction having a vertically upward component. In the case where the outer and inner structures are provided such that the common center line thereof is vertical, the separating portions extend upward from the respective upper surfaces of the blades, and are rotated about the common center line as the blades are rotated. When noodle-like chips entangled with one another are cast downward onto the separating portions, the separating portions engage respective portions of the chips and draw the same around, thereby separating the same from the remaining portions of the chips. Simultaneously, respective leading edges of the blades engage respective portions of the noodle-like chips entangled with one another, and draw the same around, thereby separating the same from the remaining portions of the chips. The shape of each of the blades of the chip breaking apparatus in accordance with the second feature (2) is not limited to that of each of the blades of the chip breaking apparatus in accordance with the first feature (1). However, it is desirable that the blades of the apparatus in accordance with the second feature (2) have the same shape as that of the blades of the apparatus in accordance with the first feature (1). In the latter case, the chip breaking apparatus in accordance with the second feature (2) enjoys the same advantages of the chip breaking apparatus in accordance with the first feature (1). The above description relates to the case where the common center line of the outer and inner structures is vertical. Even if the common center line of the outer and inner structures may be inclined relative to the vertical direction, the chip breaking apparatus can enjoy similar advantages, so long as the separating portions extend from the blades in a direction having a vertically upward component and the chips are cast downward onto the separating portions. Basically, the separating portions extend from the blades in a direction parallel to the center line of the inner structure. However, the separating portions may extend in a direction inclined relative to the center line of the inner structure.
(3) According to a third feature of the present invention that includes the second feature (2), each of the separating portions comprises a plate-like portion. The plate-like portion may be flat or curved so long as it has a substantially uniform thickness. It is desirable that the plate-like separating portions be inclined relative to the rotating direction, because those separating portions can easily engage or catch noodle-like chips irrespective of where in a radial direction those chips are cast in the present apparatus. However, a single plate-like portion may be replaced with one or more bar-like portions. In the case where each separating portion is provided by a plurality of bar-like portions, it is desirable that the bar-like portions be located at different positions in the radial direction of the outer structure.
(4) According to a fourth feature of the present invention that includes the second or third feature (2) or (3), the second direction is substantially parallel to the first direction. In this case, the separating portions can be easily formed.
(5) According to a fifth feature of the present invention, there is provided an apparatus for breaking chips into fragments, comprising an outer structure; an inner structure which is provided inside the outer structure such that the inner structure is concentric with the outer structure; a rotary drive device which rotates, in a rotating direction, at least one of the inner and outer structures relative to the other of the inner and outer structures, about a common center line of the inner and outer structures; the outer structure including a cylindrical portion, and an outer spiral blade portion which spirally projects from an inner circumferential surface of the cylindrical portion; and the inner structure including a central portion which is concentric with the cylindrical portion of the outer structure, and an inner spiral blade portion which extends radially from an outer circumferential surface of the central portion to a position in vicinity of the outer spiral blade portion, and which is inclined relative to the rotating direction such that at least one of a direction in, and an angle by, which the inner spiral blade portion is inclined differs from a corresponding one of a direction in, and an angle by, which the outer spiral blade portion is inclined, the inner spiral blade portion cooperating with the outer spiral blade portion to break the chips into the fragments. In the present apparatus, the outer and inner spiral blade portions can easily bite noodle-like chips entangled with one another and break the same into considerably small fragments. When the outer and inner structures are rotated relative to each other, the outer and inner spiral blade portions are moved relative to each other, while breaking the chips in a gap defined therebetween. The chips may be broken by a shearing or a tearing action of the two spiral blade portions. In the case where the chips are broken by the tearing action of the two spiral blade portions, the gap defined between the two (i.e., outer and inner) spiral blade portions may have a width which is, e.g., not smaller than 0.5 mm, not smaller than 1.0 mm, not smaller than 2.0 mm, or not smaller than 3.0 mm. That the respective directions of inclination of the outer and inner spiral blade portions with respect to the rotating direction differs from each other means, for example, that in the case where the outer blade portion runs in a downward direction as it runs in the rotating direction, the inner blade portion runs in an upward direction as it runs in the same direction, and vice versa, or that in the case where the outer blade portion runs in a rightward direction as it runs in the rotating direction, the inner blade portion runs in a leftward direction as it runs in the same direction, and vice versa. The angle of inclination of the outer or inner spiral blade portion with respect to the rotating direction takes an acute angle as measured in one of opposite directions, and takes an obtuse angle as measured in the other direction, or vice versa. As far as the present application is concerned, the angle of inclination of the outer or inner blade portion is defined as taking an acute angle. Therefore, even in the case where the two blade portions are inclined in the same direction with respect to the rotating direction, the respective inclination angles of the two blade portions with respect to the rotating direction may differ from each other; and even in the case where the respective inclination angles of the two blade portions with respect to the rotating direction are equal to each other, the two blade portions may be inclined in different directions, respectively, with respect to the rotating direction. Since the direction and/or angle of inclination of the inner blade portion differ or differs from the direction and/or angle of inclination of the outer blade portion, the two blade portions do not break all at once the chips over a wide range corresponding to the shorter one of the respective lengths of the two blade portions, unlike in the case where the direction and angle of inclination of the inner blade portion are the same as those of the outer blade portion. Therefore, the rotary drive device can be of a small size that exhibits a considerably low performance. In addition, respective maximums of the noise and vibration produced when the chips are broken can be reduced. In the case where the outer and inner structures are provided such that a common center line thereof is parallel to a direction having a vertical component, in particular, is vertical, the gravity exerted to the chips helps the two blade portions effectively bite the chips. However, it is not essentially required that the common center line of the outer and inner structures be parallel to a direction having a vertical component. In the latter case, it is possible to employ, e.g., a chip moving device which moves the chips in a direction having a component parallel to the center line of the outer and inner structures. Two or all of the first, second, and fifth features (1), (2), and (5) may be arbitrarily combined with each other or one another.
(6) According to a sixth feature of the present invention that includes the fifth feature (5), at least one of the outer spiral blade portion and the inner spiral blade portion comprises a plurality of separate portions which are separate from each other in the rotating direction. In this case, the plurality of spiral separate portions define a plurality of spaces therebetween about the common center line of the outer and inner structures. Accordingly, noodle-like chips entangled with one another can easily enter those spaces, and the two spiral blade portions can easily bite those chips.
(7) According to a seventh feature of the present invention that includes the sixth feature (6), the plurality of separate portions are located at a same position in a reference direction parallel to the common center line. In this case, the angle of inclination of each of the separate spiral blades with respect to the rotating direction can be increased while the overall length of the present apparatus in the reference direction can be decreased and the chances of breaking of the chips can be increased. However, the separate spiral blades may be arranged along a single spiral curved line. If the inner spiral blade portion of the present apparatus in accordance with the seventh feature (7) comprises a plurality of separate portions and if the apparatus in accordance with each of the first to fourth features (1) to (4) additionally comprises an outer spiral blade portion, the latter apparatus is readable on the former apparatus, because the plurality of blades of the latter apparatus are readable on the plurality of separate portions as the inner spiral blade portion of the former apparatus. If the plurality of inner separate spiral blades are employed in combination with the outer spiral blade portion and if the outer spiral blade portion is inclined such that the outer blade portion runs downward as it runs in the rotating direction, the outer blade portion functions as a guide member which guides, in a downward direction owing to the effect of inclination of the guide member, the chips which are rotated with the inner separate blades and are forcedly engaged with the guide member by centrifugal forces.
(8) According to an eighth feature of the present invention that includes any one of the fifth to seventh features (5) to (7), the rotary drive device comprises an inner-structure rotating device which rotates the inner structure relative to the outer structure. In this case, the chips are rotated with the inner spiral blade portion and are forcedly engaged with the outer spiral blade portion by centrifugal forces. Thus, the two blade portions can easily bite the chips. However, the outer structure may be rotated relative to the inner structure. In the latter case, it is needed to provide a fixed housing outside the outer structure, for avoiding safety hazards. Since the apparatus in accordance with the eighth feature (8) need not employ the fixed housing outside the outer structure, the apparatus enjoys a simple construction.
(9) According to a ninth feature of the present invention that includes any one of the first to eighth features (1) to (8), the common center line is substantially vertical. In this case, the gravity exerted to the chips most effectively helps the outer and inner spiral blade portions bite the chips.
(10) According to a tenth feature of the present invention, there is provided an apparatus for breaking chips into fragments, comprising an outer structure; an inner structure which is provided inside the outer structure such that the inner structure is concentric with the outer structure; a rotary drive device which rotates, in a rotating direction, at least one of the inner and outer structures relative to the other of the inner and outer structures, about a common center line of the inner and outer structures; the outer structure including a cylindrical portion, and an outer breaking portion which projects from an inner circumferential surface of the cylindrical portion; and the inner structure including an inner breaking portion which cooperates with the outer breaking portion to define a gap therebetween whose width cannot cause the chips to be sheared by the inner and outer breaking portions. In the case where the width of the gap is very small, the inner and outer breaking portions can break, by shearing, the chips in the gap. On the other hand, in the case where the gap is considerably wide, the two breaking portions cannot break the chips by shearing. In the latter case, the two breaking portions break the chips by tearing and/or striking. The width of the gap that cannot cause the chips to be sheared by the two breaking portions may be not smaller than 0.5 mm, not smaller than 1.0 mm, not smaller than 2.0 mm, or not smaller than 3.0 mm. In the case where the chips are broken into fragments without being sheared, those fragments are free of sharp burrs which would be produced when the chips are broken by shearing. In addition, since the chips are more likely bitten into the wide gap between the inner and outer breaking portions, the chips are more likely ground by the two breaking portions. Thus, an amount of fragments with sharp burrs is decreased. Fragments free of sharp burrs do not hurt the workers and, since those fragments do not bite one another so strongly, they are easy to treat. In the case where those fragments are conveyed through a conveying passage by utilizing an air flow, they do not damage the inner surface of the conveying passage. Thus, the life expectancy of the conveying passage is increased.
(11) According to an eleventh feature of the present invention that includes the tenth feature (10), at least one of the outer breaking portion and the inner breaking portion is provided along a line which is inclined relative to a reference direction parallel to the common center line. In this case, as the outer and inner structures are rotated relative to each other, the breaking of the chips occurs at a plurality of relative rotation positions between the two structures. Therefore, the rotary drive device may be of a smaller size that exhibits a lower performance, as compared with the case where the breaking occurs all at once at a single relative rotation position of the two structures. In addition, respective maxima of the noise and vibration produced when the chips are broken can be reduced.
(12) According to a twelfth feature of the present invention that includes the tenth or eleventh feature (10) or (11), at least one of the outer breaking portion and the inner breaking portion has a recess, and the other of the outer and inner breaking portions has a projection which is fitted in the recess such that the gap is left between the projection and the recess. Since the inner and outer breaking portions have the recess and the projection, the gap can be so long that the chips can more likely be broken. Thus, the efficiency of breaking of the chips can be increased.
(13) According to a thirteenth feature of the present invention that includes any one of the tenth to twelfth features (10) to (12), at least one of the outer breaking portion and the inner breaking portion comprises a plurality of breaking blocks each one of which is detachably attachable independent of the other breaking block or blocks. In this case, only a worn or damaged breaking block can be replaced with a new (or repaired) breaking block. This costs much lower than the case where the inner or outer breaking block is provided by an integral large breaking block.
(14) According to a fourteenth feature of the present invention that includes the thirteenth feature (13), the plurality of breaking blocks are provided along a line which is inclined relative to a reference direction parallel to the common center line. In this case, the inner and/or outer breaking portions or portion can be easily provided along a line which is inclined relative to the common center line.
(15) According to a fifteenth feature of the present invention that includes the fourteenth feature (14), the outer breaking portion comprises the plurality of breaking blocks, the cylindrical portion of the outer structure has a plurality of through-holes which are formed through a thickness of the cylindrical portion, and the breaking blocks are externally fitted in the through-holes, respectively, and thereby fixed to an outer circumferential surface of the cylindrical portion. In this case, the breaking blocks can be strongly fixed to the outer surface of the cylindrical portion of the outer structure, in the state in which respective attachment portions of the breaking blocks do not project into the inner space of the cylindrical portion. In addition, since the breaking blocks can be easily removed from the cylindrical portion, by the worker who is outside the cylindrical portion, he or she can easily check or repair the breaking blocks or replace one or more blocks with one or more new or repaired blocks.
(16) According to a sixteenth feature of the present invention that includes any one of the tenth to fifteenth features (10) to (15), the other of the outer breaking portion and the inner breaking portion is provided along a line which is parallel to a reference direction parallel to the common center line. Since the other of the outer and inner breaking portions that is provided along a line parallel to the common center line can be easily produced, the production cost can be reduced as compared with the case where both of the two breaking portions are provided along a line which is inclined relative to the common center line.
(17) According to a seventeenth feature of the present invention that includes the sixteenth feature (16), the other of the outer breaking portion and the inner breaking portion comprises an integral breaking block extending in the reference direction. The above-mentioned one of the outer and inner breaking portions that is provided along a line which is inclined relative to the common center line can be provided by an integral breaking block extending along the inclined line. In this case, however, the integral breaking block cannot help having a complicated shape, which leads to increasing the production cost. This problem does not occur to the integral breaking block which is employed as the other of the outer and inner breaking portions that is provided along a line parallel to the common center line.
(18) According to an eighteenth feature of the present invention that includes any one of the tenth to seventeenth features (10) to (17), the inner structure includes a central portion and a plurality of radial arms which extend radially outwardly from the central portion and each of which has a free end portion providing the inner breaking portion. Since the plurality of radial arms provide a plurality of inner breaking portions, respectively, a space which allows the presence and movement of the chips is provided between each pair of adjacent inner breaking portions and between a corresponding pair of adjacent radial arms. Therefore, the efficiency of breaking of chips is increased. In a particular case where the inner breaking portions are detachably attached to the radial arms, respectively, only a worn or damaged inner breaking portion can be replaced with a new or repaired one. This costs lower as compared with the case where the inner breaking portions are integrally formed with the radial arms.
(19) According to a nineteenth feature of the present invention that includes any one of the tenth to eighteenth features (10) to (18), the cylindrical portion of the outer structure has an opening which is formed through a thickness of the cylindrical portion, and the apparatus further comprises a sieve plate which has a number of holes and which covers the opening of the cylindrical portion. The sieve plate allows the passing therethrough of only fragments whose size can pass through the holes of the sieve plate. Fragments whose size cannot pass through the holes of the sieve plate are kept in the space between the inner and outer structures and are further broken. Thus, the fragments which have passed through the sieve plate do not include too large pieces.
(20) According to a twentieth feature of the present invention that includes the nineteenth feature (19), the chip breaking apparatus further comprises a fragment receptacle which is provided outside the sieve plate, which receives the fragments which have passed through the sieve plate, and which collects the received fragments in a lower portion thereof. The fragments collected in the lower portion of the fragment receptacle can be easily treated. For example, the fragments can be easily conveyed by a fragment conveying device which is employed in the apparatus in accordance with the twenty-first feature (21) described below.
(21) According to a twenty-first feature of the present invention that includes the twentieth feature (20), the chip breaking apparatus further comprises a fragment conveying device which conveys, by utilizing an air flow, the fragments collected in the lower portion of the fragment receptacle to outside the apparatus.
(22) According to a twenty-second feature of the present invention that includes the twentieth or twenty-first feature (20) or (21), at least a portion of the fragment receptacle is displaceable between an operative position where the portion of the receptacle externally covers the sieve plate with a space being left therebetween, and a retracted position, away from the operative position, where the portion of the receptacle permits access to the sieve plate. In the state in which the fragment receptacle is held at its retracted position, the worker can access to the sieve plate and/or the fragment receptacle, for example, can observe the plate and/or receptacle with his or her eyes, or touch the same with his or her hand. Thus, the worker can easily check or repair the same.
(23) According to a twenty-third feature of the present invention that includes the twenty-second feature (22), the portion of the fragment receptacle is pivotable between the operative position and the retracted position. In this case, the fragment receptacle can be easily moved with a simple structure.
(24) According to a twenty-fourth feature of the present invention that includes any one of the tenth to twenty-third features (10) to (23), the common center line is substantially vertical.
(25) According to a twenty-fifth feature of the present invention, there is provided an apparatus for breaking chips into fragments, comprising an outer structure; an inner structure which is provided inside the outer structure such that the inner structure is concentric with the outer structure; a rotary drive device which rotates, in a rotating direction, the inner structure about a substantially vertical center line thereof; the outer structure including a cylindrical portion, an outer spiral blade portion which spirally projects from an upper portion of an inner circumferential surface of the cylindrical portion, and an outer breaking portion which projects from a lower portion of the inner surface of the cylindrical portion; the inner structure including a central portion which is concentric with the cylindrical portion of the outer structure, and an inner spiral blade portion which extends radially from an outer circumferential surface of the central portion to a position in vicinity of the outer spiral blade portion, and which is inclined relative to the rotating direction such that at least one of a direction in, and an angle by, which the inner spiral blade portion is inclined differs from a corresponding one of a direction in, and an angle by, which the outer spiral blade portion is inclined, the inner spiral blade portion cooperating with the outer spiral blade portion to break the chips, the inner structure further including an inner breaking portion which projects radially from the central portion below the inner spiral blade portion and which cooperates with the outer breaking portion to define a gap therebetween whose width cannot cause the chips to be sheared by the inner and outer breaking portions; and at least one of the outer breaking portion and the inner breaking portion being provided along a line which is inclined relative to a reference direction parallel to the substantially vertical center line. The present chip breaking apparatus includes the above-described fifth and eleventh features (5), (11), and accordingly enjoys the same advantages as the combined advantages of the features (5), (11). The present apparatus may further include any one of the sixth to ninth features (6) to (9) and the twelfth to twenty-fourth features (12) to (24). In addition, the present invention may be so embodied as to include the fifth and tenth features (5), (10), or include any one of the first to fourth features (1) to (4) and the tenth or eleventh feature (10) or (11).
(26) According to a twenty-sixth feature of the present invention that includes any one of the fifth to twenty-fifth features (5) to (25), the common center line is parallel to a reference direction having a vertical component, and the apparatus further comprises a plurality of air flowing blades which are provided adjacent to a lower end portion of the inner structure such that the plurality of air flowing blades are concentric with the inner structure and which are rotated about the common center line to generate an air flow directed toward the inner structure. In the present chip breaking apparatus, the chips present between the outer and inner structures tend to move downward because of their own weights. However, the chips are moved upward by the air flow generated by the air flowing blades provided adjacent to the lower end portion of the inner structure. In addition, the air flowing blades have the function of repelling up the chips colliding therewith. In this sense, the air flowing blades can be called as chip repelling blades. Since the space between the outer and inner structures includes a portion in which air flows fast, and a portion in which air flows slow, the chips are moved downward by their own weights on one hand, while being moved upward by the air flow on the other hand. During the downward and upward movements, the chips are bitten and broken by the outer and inner breaking portions. The air flowing blades may be ones which are rotated together with the inner structure, or ones which are rotated at a speed different from the speed at which the inner structure is rotated. In the latter case, the air flowing blades may be rotated directly by an exclusive rotary drive device, or indirectly by the rotary drive device of the inner structure via a rotation-speed changing device, such as a step-up or step-down gear, which transmits the rotation of the rotary drive device to the blades at a changed speed different from the original speed of rotation of the drive device. Anyway, the inner structure and the air flowing blades can be rotated at respective appropriate speeds.
(27) According to a twenty-seventh feature of the present invention, there is provided an apparatus for breaking chips into fragments, comprising a first-stage breaking device which breaks a plurality of elongate chips which are entangled in each other, while untangling the entangled elongate chips; and a second-stage breaking device which further breaks the chips broken by the first-stage breaking device, into fragments. The chip breaking apparatus in accordance with the twenty-fifth feature (25) is readable on the present apparatus in accordance with the twenty-seventh feature (27). In addition, the first-stage breaking device may include any one, any two, or all of the first, second, and fifth features (1), (2), (5), and the second-stage breaking device may include the tenth feature (10).
(28) According to a twenty-eighth feature of the present invention that includes the twenty-seventh feature (27), the second-stage breaking device comprises a sieve member having a number of holes, and the second-stage breaking device continues breaking the chips to the fragments having a size which can cause the fragments to pass through the holes of the sieve member.
(29) According to a twenty-ninth feature of the present invention that includes any one of the first to ninth features (1) to (9), the rotary drive device rotates the at least one of the inner and outer structures relative to the other of the inner and outer structures, at a velocity not less than 800 rotations per minute. The present chip breaking apparatus has a construction which can be rotated at a high velocity or speed and accordingly can break chips at a high efficiency. In the case where the rotation velocity is predetermined at not less than 1,000 rotations per minute, not less than 1,200 rotations per minute, or not less than 1,400 rotations per minute, the present apparatus can break chips at a higher efficiency.
(30) According to a thirtieth feature of the present invention that includes any one of the tenth to twenty-eighth features (10) to (28), the rotary drive device rotates the at least one of the inner and outer structures relative to the other of the inner and outer structures, at a velocity not less than 800 rotations per minute.
(31) According to a thirty-first feature of the present invention, there is provided a chip treating system comprising a chip breaking apparatus according to any one of the first to twentieth and twenty-second to thirtieth features (1) to (20) and (22) to (30); and a fragment conveying device which conveys, by utilizing an air flow, the fragments output from the chip breaking apparatus. The present system can easily treat chips. In particular, since the chip breaking apparatus in accordance with any one of the tenth to nineteenth and twenty-fourth to thirtieth features (10) to (19) and (24) to (30) is suitable for breaking chips into small fragments with less sharp burrs, and the chip breaking apparatus in accordance with any one of the twentieth, twenty-second, and twenty-third features (20), (22) and (23) is suitable for collecting small fragments at a single place, those chip breaking apparatuses are suitable for use with the fragment conveying device which utilizes an air flow for conveying the fragments.
(32) According to a thirty-second feature of the present invention that includes the thirty-first feature (31), the chip breaking apparatus has an outlet through which the fragments are discharged, and the fragment conveying device has a fragment conveying passage whose one end is connected to the outlet, and an air-flow generating device which generates, in the fragment conveying passage, an air flow in a direction away from the outlet.
(33) According to a thirty-third feature of the present invention that includes the thirty-second feature (32), the air-flow generating device comprises an air suction device which generates the air flow by sucking air in a downstream-side portion of the fragment conveying passage that is distant from the outlet of the chip breaking apparatus. It is desirable that the present chip treating system further include, on an upstream side of the air suction device, a fragment separating device which separates the fragments from the air, and/or a filter device which removes foreign matters from the air.
(34) According to a thirty-fourth feature of the present invention that includes the thirty-second or thirty-third feature (32) or (33), the air-flow generating device comprises a pressurized-air-utilizing air-flow generating device which includes an air blowing nozzle which is provided at the one end portion of the fragment conveying passage that is connected to the outlet of the chip breaking apparatus, such that an axial direction of the nozzle is parallel to a lengthwise direction of the passage; and a pressurized-air supplying device which supplies a pressurized air to the air blowing nozzle, so that the pressurized air is blown from the nozzle into the passage, an air pressure around the nozzle is lowered, and accordingly the air flow is generated in a direction from the outlet toward the passage, and in the direction away from the outlet in the passage.
(35) According to a thirty-fifth feature of the present invention that includes any one of the thirty-first to thirty-fourth features (31) to (34), the chip treating system comprises a plurality of chip breaking apparatuses each according to any one of the first to twentieth and twenty-second to thirtieth features (1) to (20) and (22) to (30), and the fragment conveying device comprises a fragment conveying and collecting device which conveys, by utilizing the air flow, the fragments output from the plurality of chip breaking apparatuses and collects the fragments at a common place. For example, the present chip treating system may be employed in a factory in which a plurality of machine tools are used. Each of the chip breaking apparatuses of the present system breaks the chips produced from a corresponding one of the machine tools, or two or more corresponding machine tools that are adjacent to each other, and the fragment conveying and collecting device collects, at a single place, the fragments output from all the chip breaking apparatuses. Thus, the present system can easily treat the chips produced from the factory.